health benefits of water. A lot of us are drinking more water than ever. Buts a ABC's Sara Haines, she has the story of a woman who took it to the max. Perhaps too far. Reporter: Celebrities swear by it. From Gwyneth paltrow to Jessica alba. Even Jennifer Lopez. A-listers with glowing skin who credit drinking lots of water as one of their beauty secrets. So, one New York City health care journalist put it to the test herself. Drinking three liters of water a day, to see if it would improve her skin. I went -- I found this girl. Beautiful skin. Beautiful hair. And she said she drinks three liters of water a day. My skin is dry. I would see how it works. Reporter: For one week, she drank three liters of water a day. That's a little more than 8 12-ounce glasses of water. A tip that helped her drink all this water, a straw. It goes faster. It's easier for me. Reporter: She didn't change anything about her diet, and kept her Normal gym routine. Did you see any results? Yeah. I definitely did. I felt like I was sleeping better. And I felt like my skin looked fuller. Reporter: In addition to feeling healthier, she also lost two pounds. People talk about weight loss with water, too. Were you as hungry? That's another thing. I wasn't hungry as much. When you're hungry, you're not really hungry. You're just thirsty. Reporter: But there was one pitfall to the experiment. Using the bathroom. I know it seems like a natural thing. But using the bathroom, seven, eight times during a work day was going almost every hour. Reporter: To celebrate Sabrina's success -- I'm sorry. Reporter: The two of us toasted. With water, of course. I can't keep up with you. Reporter: For "Good morning America," Sara Haines, ABC news, New York. You were probably a fun girl in college. We asked you in our flash poll, would you drink three liters of water to improve your health? 72% said you would. 28% not so much. A little bit of an overload. We want to ask Dr. Richard Besser, what do you think? If you don't drink enough water, that's not good. You get dehydrated. Your skin's going to look bad. You're going to feel terrible. But drinking water to the extreme, there's nothing to show it will benefit you. Our kidneys regulate it very finely. If you surpass what your kidneys put out, you can get water intoxication. That can lead to seizures. Water intoxication? Yes. Some people have died from drinking too much water. What's not enough water? If you don't drink enough water? What's not enough? In reality, the amount of water she's drinking, three liters a day, isn't that much. An average man, three liters is about what's recommended. Looking at that tray, that feels about right. I drink that in a day. But I do it by listening to my body. I don't think I could do that. I don't. And -- but -- I mean -- yeah. I don't go to the bathroom as much as you guys. That's the thing. She was going to the bathroom eight times in a day. And your brain controls your thir and if you're thirsty, you need to drink more. And that's really all you have to -- this is making it too complicated. If you listen to your body. If you go to the bathroom every hour, you're probably drinking too much. Is it true that if your brain tells you, you're thirsty, it's too late? You're already dehydrated? That's a myth. But if you're exercising, you need to drink ahead of time. Drink ahead, before you do your workout. Your body's thirsty is telling you it's thirsty. Why would we be designed that by the time our body is telling us we need to drink more, it's too late? I don't know. Somebody made it up. I've been waiting a long time. I drink it all the time. It's better than any --

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